"Using our model, we are beginning to answer that question, and it looks like infection does precede inflammation," study author Dr. David Stoltz, an assistant professor of internal medicine at the University of Iowa, said in a news release from the school. "The importance of that finding is that it could dictate what types of therapy we might use. Knowing that infection is first suggests that if we can prevent or fight infection, then that might delay or prevent the lung disease in people with CF."

Most of the deaths and disability in people with CF result from lung disease.

The findings also appear to suggest that lung infections in children with cystic fibrosis should be treated early and aggressively, Stoltz said.

The researchers reached their conclusions by studying pigs with a genetic mutation that causes cystic fibrosis.

"This is a really great example where the pig serves as a model for what happens in the human, and the pig reacts to this disease in nearly the same way," study co-author Randall Prather, distinguished professor of reproductive biotechnology at the University of Missouri, said in the news release. "In contrast, when you use mice, they don't get the lung disease that is common in patients with cystic fibrosis."

The study was published online April 28 in the journal Science Translational Medicine.